


Heated Mistakes

by JellyFicsnFucks



Category: Undertale (Video Game)
Genre: Blow Jobs, Blow Jobs With Teeth, Boot Worship, Cock Piercing, Cock Slapping, Cock Worship, Implied/Referenced Cheating, Large Cock, Mating Cycles/In Heat, Rating Changed
Language: English
Status: Completed
Published: 2019-04-25
Updated: 2019-10-12
Packaged: 2020-01-31 22:08:18
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,031
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18600346
Author URL: https://archiveofourown.org/users/JellyFicsnFucks/pseuds/JellyFicsnFucks
Summary: “Hmmm?  So Your The Type Who Finds It Easier To Fuck Themselves. Nyeh Heh. Not Much Of A Difference From Selfcest To Incest If You Ask Me. Besides. We’re Not Even Related. … I’m Just Another Papyrus. Same Name. Different Face. Better Timeline. Bigger Package, That, I Can Promise. Besides, I’ve Been Wanting to Pound Your Bones Into Dust Since We Met. What Do You Say? Wanna Fuck? ”Sans gulped… a bead of sweat ran down his neck as he eyed Fell up and down.  “...okay.”





	1. Chapter 1

Papyrus twitched as that wonderful aroma passed under his nasal cavity, the smell of his brother was wafting downstairs and overtaking the pasta dish he was making. He stirred his pot angrily, trying to ignore the waft of a monsters heat... but it was no good. His brother was very distracting!

 Papyrus stomped upstairs and knocked hard on his brothers door. Though with gloves the heavy handed knocking was muffled and sounded like poofs of air. Still, Sans responded with a strained “go away pap…”

 Papyrus crossed his arms over his chest. “I KNOW YOUR IN HEAT SANS! I’M NOT KICKING YOU OUT OR ANYTHING… BUT COULD YOU PLEASE GO TO RED’S PLACE AND DEAL WITH THIS PROPERLY?! IT'S NOT HEALTHY TO STAY COOPED UP IN YOUR ROOM! … AND YOUR RUINING MY PASTA!”

 “uuuugh~” The zombie like voice from the other side of the door was accompanied by a shuffle and a clatter of bones. Slippers dragged across the floor and a hand rattled along the door knob to remove the lock. Finally, Sans peeked his head outside, just an eye. Enough to see his brother, while still being hidden by the door frame.

 The smell of his heat was even stronger now that the door was cracked open. Papyrus jolted backwards and slid a gloved hand over his face before the smell became too intoxicating. The second thing he noticed was how pale and bluish his brother looked, like his magic was leaking to the surface of his bones and making him flush in a blueish hue. The third thing he noticed was the bare shoulder blade, just poking it's way into vision from the small crack in the door. It wasn’t revealing or anything… but the lack of a sleeve told Papyrus his brother was naked and using the door as a cover.

 “red won’t pick up his phone…” Sans sighs. His breath is like lavender and sweetened milk and Papyrus jumps back again, this time lifting the hem of his cool dude shirt to raise over his nose. He looks ridiculous with his shirt folded inside out but this was a necessary precaution!

 ...also he’s revealing his ribs to his brother, which didn’t help Sans’s situation in the slightest.

 “IF RED WON’T PICK UP HIS PHONE THEN YOU’LL JUST HAVE TO GO TO UNDERFELL ON YOUR OWN!” Papyrus urges. “IF YOU DON’T GET RID OF YOUR HEAT IT WILL START AFFECTING YOUR HEALTH!... AND MINE!” He emphasizes, more to the point as he takes another step back and waggles a warning finger at Sans from the stair banisters. Retreating slowly from the scent of flowers wafting from his brothers room. “YOU NEED TO GO SEE HIM! NOW! I …. I NEED TO GO VISIT UNDYNE. SHE HAD TRAINING FOR ME. I THINK. SURE. OKAY? I’LL TURN OFF THE STOVE.”

 “uhhhhhh…” Sans groans. He closes the door to his room and lies back against the door frame. The cool door feels nice… but it doesn’t stay cool for long. Facing the inside of his room he scanned the floor for whatever he’d abandon his shorts. Right now he was only wearing his fuzzy slippers… and as appealing as it was to go see Red wearing nothing… he’d have to walk outside first to even make that happen.

 He picks up his shorts… but drops them immediately and a wet -kerplunk- hits the ground. Soaked all the way through, he can’t wear those again. He groans and turns to his dresser to find some fresh clothes. It didn’t matter what he choose. It would just come off as soon as he arrived at Red’s house anyway…

 He ended up wearing a black tee and pajama bottoms with smiley faces. It was tacky but it would be enough to temporarily step outside. Sweat dripped down his neck and he dressed and through open his bedroom door.

 “paaap…. ‘mm going to red’s.” He announces just because the brothers always announce where they are going before they leave. Sans grabs the banister and pulls himself down like a mime act. The bottom step is the hardest to conquer, because he’s out of banister.

 He spots Pap by the door. Waiting for him.

 Sans blushes, embarrassment swelling up inside him. He didn’t mean to stink up the house with his heat… it came unexpectedly…   and it looked like Pap had packed to sleep over at Undynes until the smell dissipated. His brother is wearing a mask right now to shield his mouth and nose from the noxious odor. Sans cups his hands against his face. “sssorry.” He cries pathetically.

 “IT'S FINE, BROTHER!” Papyrus assures him. “IT HAPPENS TO EVERYONE…IT JUST MEANS YOUR BODY IS READY FOR A FAMILY!” He puts an arm around San’s shoulder to guide him out, but the slight touch makes his brother shriek with an alarming sensitive squeal.

 Papyrus blushes at the noise and tries to look anywhere but at his brother. He pretends he doesn't hear it, all the while Sans wants to curl up and cry because he’d made such an embarrassing sound.

 They walk out together and Pap locks up the house, before dropping the key in the abandoned mailbox of his. Sans waves goodbye to his bro, as they part. “sleep well pap.” He trembles.

 “YOU TOO! TRY TO GET SOME SLEEP!” Papyrus tells him and waves as he’s already making his way to Undynes. Sans chuckles, and holds his arms into himself to hold back from humping a snow poff. ‘Try to get some sleep’ … would be impossible for him. He needed to go see Red. He whines in his throat and checks his phone again, but there's still no answer.

 “red...where are you??” Sans whines. He walks behind the house to the machine in the lab. There’s a simple switch and a hum and a ding. - Like teleporting to an alternate universe was as easy as making toast.

 Sans slumps out of the machine and huffs as he feels his body quake with need. His heat had been painful for a while now… and no matter how many times he came he still couldn’t reach that level of satisfaction. He must have smelled like sweat, he felt like he was drenched in it…even his new layer of clothes started to feel sticky and wet.

 He teleports into the Red’s house. It’s rude. But there was really no point to knock.  If someone was home they’d have to go through 10 layers of locks before they could open the front door for him. If no one was home he’d teleport inside anyway.

 Fell is in the kitchen, giving a surprised jump when Sans teleports inside. He’s almost about to yell at the double when he sees the state the skeleton is in and his jaw drops. “Oh.” Fell raised his bone brows with a snarky grin. “Here For Red? … He’s Out Today.”

 Sans whines, he holds his midsection, trying to stop his soul from leaking out on the carpet. The drip of ectoplasm was crawling down his chest cavity in small drips.  “out where? … will he be back soon??”

 “He’s On A Trip To The Capital. Asgore Himself, Invited Sans For A Demonstration Of His Power. It’s A Promotion. He’ll Probably Be Gone All Day. Paperwork And New Duties To Fulfill And All….” Fell tilts his head, watching the pile of bones squirm. “I Could Help With Your Heat.”

 “...you?” Sans’s face twists in disgust. “i could never do it with… well.. someone who had my brothers face.”

 “Hmmm?  So Your The Type Who Finds It Easier To Fuck Themselves. Nyeh Heh. Not Much Of A Difference From Selfcest To Incest If You Ask Me. Besides. We’re Not Even Related. … I’m Just Another Papyrus. Same Name. Different Face. Better Timeline. Bigger Package, That, I Can Promise. Besides, I’ve Been Wanting to Pound Your Bones Into Dust Since We Met. What Do You Say? Wanna Fuck? ”

 Sans gulped… a bead of sweat ran down his neck as he eyed Fell up and down.  “...okay.”


	2. Nsfw Kedgeup

He followed Fell up the stairs, quietly. The small taps of boots against the stairs made him pause to figure out what he was getting into. Sex with Fell.  _  oh!  _ He shivered with nerves. 

He didn’t think Boss could smile with fangs. Yet he looked so intimidating and handsome. Fell’s teeth were the first thing Sans thought about when he agreed. He imagined how gratingly good it would feel to thrust into that dangerous jaw. Sans was turned on by those jagged teeth. 

When he’d been with Red, he was wary of the sharpened canines …  at first. Soon the light pressure of teeth dragging along the underside of his dick was an extra stimulant. An excited thrill passed him every time he forced that mouth open wider. The beaded piercing on Red’s tongue, accompanied by his sharp protruding teeth were a whole new sensation he eagerly push into, drowning in the pleasure of the new feeling. 

Did fell have a piercing like that? He’d never really paid attention to the other Papyrus, but now his eyes were scraping him for answers. Boss had scars around any visible bone. There would probably be more once they got past that layer of clothing.

Fell opened his bedroom door and seated himself on the side of the bed, legs opened invitingly for a person to sit between. His boots tapped the ground impatiently, yet his demeanor was slumped forward.  The charismatic skeleton had his neck turned upwards, his dark eyes half lidded as he uttered a command. “Well? What Are You Waiting For? Get to work.”

Sans shook his head. A little too quickly for Fells liking, a growl passed his teeth.  Him? Suck down Fells-?!!!  _ Impossible! _   Sans felt his cheeks turn a shade blue at the thought, the rush of magic making his bones hotter. 

_ He was the one in heat here! Not Fell! … why did he have to suck him off?! Shouldn’t it be the other way around?!! _

His daydreaming of those angular teeth suddenly crashed to a stop. He looked down from Fells jaw to the nape of his neck, to the top of his ribs just sticking out underneath his armor, down to the exposed bare spine at his hips. The iliac crests poking out over the top of his belt. Finally down to the bulge, tight against the zipped up leather fabric of his jeans. 

It certainly did look…  _ bigger  _ than Reds. Just from the swell alone he could tell it was girthy. A whine caught in his throat, his higher mind arguing about his pride and the faint linger of cheating on Red with his brother…. But his lower regions were driving his thoughts now. 

He sunk to his knees. Painfully slamming his kneecaps against the hardwood. But it didn’t matter, the scent of Fell’s crotch against his face was sickly salty and bitter and it resembled his own heat. He rubbed his cheek against the heat of the bulge. 

Closer. 

Smelling of vinegar. Of dust. Of bone and milk. Of  _ liquorice _ . Of  _ salt  _ and  _ sweat _ . Of  _ Fell _ .  His nasal cavity burned with the sharp scent, his tongue slid out - too heavy for his mouth- and lapped up the front side of the intersection of fabric. Wetly staining the jean in a darker color of saliva and heat. 

_ Fuck _ ! He didn’t think he could be this desperate for cock, but Fell’s natural dominating height made Sans feel ever so smaller. The monstrous tower above him was watching, smiling, encouraging him with an ever present loom to take in more. Sans felt  _ hot _ . Being watched by Fell…. Even if this was his potential partner today- felt foreign. It felt  _ wrong _ . Simply because it was Fell,  it felt so  _ goddamn hot _ to be watched.

Especially since he didn’t know this partners quirks. He didn’t know what Fell was thinking -with those devious slitted eyes and those gloved hands that sprawled back into the matress, keeping him upright. Restrained to touch him… curious what the small skeleton would do if left on his own. 

Hot damn, Sans wanted to know too. He didn’t think he’d be nose deep in Boss’s lap like a bitch in heat, but here he was. His mouth felt so dry. Panting for air, even though he was salivating. Lapping up at the waistband and bringing down the tip of his front teeth together to clasp around the small zipper end. Carefully pulling down, such a tiny metal piece could slip so easily from between his wet mouth. He accidentally lost it, having to reach with his tongue to find the metallic little slab again. The wet bulged up jean fabric beneath his chin was so tantalizingly out of reach…  Sans couldn’t stand it anymore. He reached up with his hands, slipping them over Fell’s thighs. 

Hard. Had Fell summoned his whole ecto body? 

That was…  _ kinky _ . 

Sans shuddered a breath, looking back up to Fell’s hips. Instead of an exposed spine, a musculature six pack ebbed in around his ecto center. His naval dipped down in a perfect v. His magic glew red. But not red like his brothers. This was the deep crimson of blood, the lacquer color of a hardwood stain finish. The red of something _ violent and poisonous.. _ . 

_ He was going to put that in his mouth.  _

Sans felt a roll of heat at that sentiment. The back of his neck beaded in sweat and his eye lights dimmed down to a lazy half lidded view as he at last unzipped Fells pants and pulled down the waistband of his boxers… 

It smacked him across the cheek with a pat. It's thick, full, length more than he could ever imagine. A vein pulsed on its underside with an arousal and, though he couldn’t see it, he felt the wet viscous bead of precum smear against the side of his skull. The smell was more intense, Sans shuddered burying his nasal cavity closer to the base of Fell’s balls.

“You’re Some  _ Sick Freak _ , Aren’t  _ You _ .”  Fell taunted him, but his insult didn’t hit. As sick as Sans was, Fell had to be just as sick to allow this to go on for so long. Seeing his cock cover half of Ketchups face was… cute. 

Certainly a  _ ‘cute’  _ attempt by a worthless flea who wouldn’t even be able to fit half his hot rod in that slippery mouth - but Fell smirked and let this play out. 

Sans on the other hand was sweating hard. 

His heat was fueled even more painful by the scent of Fell’s magic. He whipped a hand to the inside of his own pants to fondle himself- knowing it would be useless. His tired arm was still better than nothing though. With one hand draped over Fells thigh to keep him upright - and the other down his pants - Sans completed his little tripod of balance by lapping the flat of his tongue up against the side of the large phallus in front of him. 

He had to arch his back outward and dip his neck far back just to finally lap at the end of the glowing phallus. Fell hadn’t lied about his size, from base to tip he was a goddamn giant. Well endowed wasn’t even a feasible compliment. The bastard was definitely altering his magic to  _ ‘enhance _ ’ his already impressive mast. 

Sans closed his eyes, relishing in the salt and liquorish of his magic. His tongue was on fire with the bumpy texture, throbbing like it was alive against the sensitive fleshy array of taste buds.

There was a smooth metallic bulb, unlike magical skin, that Sans’ tongue curved up against. He opened his lust filled eyes.  _ Piercings _ . Two gold studded piercings aligned his dick just before the very soft and delicate fleshy center of his cocks head. The taste of cum, smeared here. Strong odor and Sans swallowed the mix of bitter magic infused saliva. 

_ Holy fuck, how was he going to swallow the whole thing? This cock was holy. Heaven sent! _

He rubbed his cheek against it again. Praying with glee that such a godly cock was going to drive him up the wall. His breathing was laboured when he took the head into his mouth again, jaw aching from the wide way his jaw stretched just to encapsle Fell’s tip. 

_ Was it possible? Oh Stars- would it even fit in him? _

Surely he was exaggerating. Fell’s cock couldn’t be that big- _ it would kill him! _ But certainly from so close it  _ looked  _ larger, looked  _ menacing _ . And yet. Fell didn’t buck into his mouth. Not even once. He was patient and well in control of his primal urges. He was letting Sans’s mouth explore. Letting Sans control the tempo, the pace of Little Fell’s felatio fun. 

That is- until Fell noticed Sans was having fun on his own too. With his fingers diddling around inside his pants, Sans was feverishly rocking in place, desperate to get off. 

“Move It.” A simple command.He nudged his boot up against Ketchups arm.  Sans moaned, sending vibrations up the tip of Fells cock. He’d never imagined he could get so horny over a few orders but with Fell hovering over him he could beg his master to let him cum.  _ Master _ ?  _ Oh stars, was Fell deserving of such a title? _

_ Maybe he was… just for today.  _

Sans pulled his hand out his pants with a low groan around Fells cock. A thick blue ectoplasm strung across each digit he’d been using. Fell’s boot immediately took their place, his heel lightly pressing into his crotch. Not hard. Just enough for Sans to feel the weight of touch around his nether regions- and desperately rock up against the only thing that could even stimulate him. 

“...You’ve gotten my boots dirty, pet.” Fell sneered, he grabbed Sans by the back of his skull and shoved him down into a deep bow to the floor. The slick blue stained boot in front of him. “Lick it clean.” 

Sans made a shallow gasp, leaning forward with a stuck out tongue. The whole flat of his tongue came across the rubber toe. “Y..yes master.” 


End file.
